Safety switch and fuse construction



Feb. 16, 1954 J. 5. FERGUSON 2,669,624

SAFETY SWITCH AND FUSE CONSTRUCTION Filed July 24, 1952 2 Sheets-Sheet 1INVENTOR JOHN S- FERGUSON BY ATTORNEY Feb. 16, 1954 J. s. FERGUSONSAFETY SWITCH AND FUSE CONSTRUCTION Filed July 24, 1952 2 Sheets-Sheet 2INVENTOR JOHN S. FERGUSON YWQ QW ATTORNEY Patented Feb. 16, 1954 SAFETYSWITCH AND FUSE CONSTRUCTION John S. Ferguson, Glenview,

Ill., assignor to Electric Machinery Manufacturing Company, Minneapolis,Minn.

Application July 24, 1952, Serial No. 300,736

15 Claims.

The herein disclosed invention relates to safety switch and fuseconstruction and has for an object to provide a construction in whichthe fuse is disposed within an enclosure having an access opening closedby a door and in which the fuse may be disconnected from the circuitwith which it is used upon opening the door.

Another object of the invention resides in providing a fuse carriermounted within the enclosure and carrying a fuse and in providing theswitch with a fuse contact connected to the fuse and movable with thecarrier having a terminal contact connected to a terminal of the circuitwith which the fuse is used and fixed relative to the enclosure, saidcarrier being pivoted to a part of said enclosure and having an areasufficient to cause said carrier to close the access opening when thedoor and switch are in open position and being adapted to bring the fusecontact of the switch into engagement with the terminal contact when thedoor is in closed position.

A still further object of the invention resides in providing aconstruction whereby the fuse carrier is moved by movement of the doorand in which the door may be moved independently of the fuse carrier topermit closing the door while the fuse carrier is in either position.

Another object of the invention resides in providing a grounding deviceoperable to ground the fuse contact of the carrier when the carrier ismoved into position to close the access openmg.

An object oi the invention resides in providing locking means forlocking the carrier in open position of the switch when the door isfully open.

Another object of the invention resides in providing a link pivoted tothe door and having a bayonet slot therein formed with a longitudinalportion and an offset portion and in providing a part movable with thecarrier with a pintle movable in said slot.

Another object of the invention resides in providing a link pivoted to apart fixed relative to the carrier and having a latch lug adapted tocooperate with a shoulder formed on a track along which said lug ridesfor the purpose of locking the carrier in open position. 4

An object of the invention resides in providing an pivoted to the doorand having a longitudinally extending slot in which a pintle carried bythe link slide, whereby the carrier be moved to open position and alongwhich the pintle may slide upon closing of the door.

An object of the invention resides in providing an arm pivoted to a partcarried by said carrier and carrying said pintle, and in providing stopmeans between said arm and part for limiting the swinging movement ofsaid arm.

A still further object of the invention resides in forming on said arm alatch lug and in providing a guide carried by the enclosure along whichsaid lug travels and in further forming said guide with a notchproviding a shoulder against which said lug may abut to restrainmovement of said closure.

Other objects of the invention reside in the novel combination andarrangement of parts and in the details of construction hereinafterillustrated and/0r described.

In the drawings:

i is a side elevational view of a safety switch and fuse constructionillustrating an embodiment of the invention with the door closed.

Fig. 2 is a plan sectional view of the structure shown in Fig. l andtaken on line 22 of Fig. 1.

Fig. 3 is an elevational sectional view looking from the opposite sideand taken on line 3-3 of Fig. 4 is a view similar to Fig. 3 showing thedoor in open position.

In the drawings a safety switch and fuse construction has been shownwhich includes a framework forming part of the control apparatus of anelectric power system with which the invention is to be used. Thisconstruction embodies an enclosure forming part of the control apparatusand including a panel forming a part of the switchboard of the controlapparatus. Within this enclosure is mounted a switch and a fuse carrierpivoted to the enclosure. This carrierhas movable switch contactscooperating with fixed switch contacts carried by the enclosure andconnected to suitable terminals of the electric line being fused. Thecarrier supports fuse clips connected to the movable contacts whichserve as a fuse holder for supporting fuses. A door is hingedlyconnected to the enclosure and has pivotally connected to it a linkhaving a slot therein and receiving a pintle attached to an arm pivotedto a part fixed relative to the carrier. When the pin reaches the outerend of said slot the opening of the door procures swinging of thecarrier and disengagement of the movable switch contact from the switchcontacts, thus deenergizing the fuse circuits and removing voltage fromthe fuses. The slot in the pivoted link is of the type known as abayonet slot and has a longitudinal portion along which the pintle mayslide permitting the door to be closed while the carrier is inswitch-opening position. The said slot further has an offset portion inwhich the pintle may be disposed and by means of which the carrier maybe moved into switch-closing position. The arm on which the pintle ismounted has formed on it a latch lug which rides along a guide having anotch providing a shoulder against which the latch lug may abut when thecarrier is in switch-opening position and which serves to maintain thecarrier in such position while the fuses are being examined or replaced.The carrier is constructed of a plate of insulating material which hasan area suflicient to substantially close the opening through theclosure and obstruct access to the live parts of the electric powersystem. A shorting device carried by the enclosure engages the fuseclips and grounds the same when the fuse carrier is in switch openingposition.

The invention is used as part of a control apparatus .for controllingand indicating the conditions of a power system or any other system inwhich electrical circuits are to be fused. A.

portion of such apparatus has been shown in the drawings and consists ofa main framework H forming part of a switchboard indicated in itsentirety by the reference numeral Hi. This framework H consists ofstiles 92 which ar arranged at spaced intervals and which are preferablyconstructed of sheet metal formed in the desired shape. The said stileshave faces I3 constructed with offsets M from which issue flanges l5disposed inwardly of the said faces. The said stiles have legs l6extending inwardly from the faces i3 and from which flanges i7 issuewhich are parallel to the faces i3. These stiles of the switchboard areconnected together by means of headers l8 similarly constructed andwhich are formed in the same manner. In addition, rails 19 are providedwhich are also connected to said stiles. These rails are alsoconstructed of sheet metal and are bent to form faces 22 with legs 23and 24 extending inwardly therefrom and from which flanges 25 and 26issue. The flanges 25 lie in continuation of the flanges l5 of thestiles i2 and the flanges I l of the said stiles lie in the plane of thecorresponding flanges of the header [8 and form a rabbet 25 extendingabout the access opening 2!. These stiles, headers and rails providesections in the switchboard having access openings 2! and through whichthe parts disposed within the same are accessible. Attached to theflanges I! are angle frame members 21 which are disposed rearwardly ofthe rails i9 and other frame members 28 which are connected into andwhich extend rearwardly from the frame members 2'1. This constructionforming no particular part of the invention, has not been shown in itsentirety, and it is to be understood that any suitable construction suchas now employed for the purpose may be used for supporting the inventionand for forming the enclosure thereof.

The access opening 2! in the main framework H is closed by means of adoor 29, best shown in detail in Fig. 1, which is received in the rabbet20. This door is constructed from sheet metal and has a panel 3! withwalls 32 bent inwardly therefrom. From these walls issue flanges 33which lie in a common plane and which are adapted to overlie the flanges25 of th rail [9 and the flanges iii of the stiles i2 and the header I8.The door 29 is hingedly supported by means of hinges 3 which are securedto leg 23 of rail l9 and to the lowermost of th walls 32 of said door.The door 29 is adapted to swing from closing position, as shown in Fig.3, to a fully open position, as shown in Fig. 4, and may be manipulatedby means of a handle 35 secured to the panel 3 l. A suitable lock, notshown in the drawings, may also be incorporated if desired.

The switch and fuse construction, forming the dominant portion of theinvention, is mounted on a switch and fuse framework 35. This'frameworkconsists of a lower frame 3! and an upper frame 38 connected together bymeans of uprights 39. The lower frame 31 consists of a front angle framemember ii, a rear angle frame member 42, and side angle frame members43. All of these frame members are welded together and to the uprights39. The upper frame 38 is similarly constructed with front angle framemembers 45, a rear angle frame member 45, and side angle frame members45. All of these frame members are welded to the upper ends of theuprights 39. The framework 36 is supported through the lower frame 3'!which rests on the angle frame member 2'5 of the main framework H andwhich is attached thereto by means of bolts 31. The framework 35 isfurther supported on other supports not shown in the drawings butforming part of the main framework i i.

The invention utilizes a fuse carrier 48 which is constructed from aslab of insulating material and which is of an area commensurate withthe area of the access opening 2|. This carrier has a tached to it atits lower end one leaf 49 of a hinge 5! which hinge extends throughoutthe length of said carrier. Bolts 52 extending through the said carrierand hinge leaf attach the hinge to the carrier. In a similar manner theother hinge leaf 53 of said hinge is secured to one of the flanges 54 ofan angle frame momber 55 by means of bolts 55. Frame member 55 ismounted on and attached to the lower frame 31 by welding or otherwise.By means of this construction the carrier 48 may move fromswitch-closing position as illustrated in Figs. 1 and 3 toswitch-opening position as shown in Fig. 4.

The particular switch and fuse construction illustrated in the drawingshas been designed for a three-wire power line and three switches 12, 13and M together with the corresponding fuse holders 15, 75 and 1'! havebeen shown. These switches and fuses are similar in construction so thatonly the switch 12 andfuse holder 15 will be described in detail.

The fuse holder 75 is supported on two insu lators 51 and 58 which havemounting plates 6! and 62 at the ends of the same. These insulators areattached to the carrier 48 by means of cap screws 59 extending throughsaid carrier and screwed into the mounting plates 51. overlying themounting plate 62 of insulator 51 is a bar 53 of conducting material.overlying this bar is a fuse clip 64 best shown in Fig. 2. Screws 65extend through said clip and said bar and are screwed into the mountingplate 62 and thus attach said bar and clip to the insulator. The bar 63is formed with a bend 66 to provide a leg 6'! issuing angularlytherefrom. This leg passes through a hole 58 in the carrier $8 and theend of the same forms a switch blade designated by the referencecharacter 59. A sleeve 1! of insulating material encircles the leg 5'!and further insulates said leg and the blade 53 from the carrier andadjoining objects. Attached to the insulator 58 is another fuse clip 18which together with the fuse clip 64 supports a cartridge fuse i9 in thecustomary manner. The insulator 58, similar to the insulator 5], hasattached to it a bar II which is bent and formed with a switch bladewhich are constructed of insulating material and which extend outwardlyfrom the carrier 48. These barriers are attached to the said carrier bymeans of clip angles I35. The corners of the said barriers are cut awayas indicated at I38 to cause the barriers to clear the framework 36 andto confine movement of said barriers to the space within said framework.These barriers are located one between each fuse and one at each end ofthe carrier.

The switch 12 is supported on two angle frame members 83 and 84connected together by means of outwardly inclined angle frame members 85All of these frame members are welded to the frame 81 and to theuprights 39. Attached to the angleframe members 83 and 84 are insulators88 and 81 which are secured in the same manner as. the insulators 5! and58. The manner of attachment is best shown in Fig. 1 in conjunction withthe insulators for the switch 14. The insulators 88 and 8! have mountingplates 88 at the outer ends of the same similar to the mounting plates62 and 8| and from which issue studs 89. Mounted on the studs are switchjaws 9| which are adapted to receive the blades 69 and 82. These jawsare held in place upon the studs 89 by means of nuts 92 and lock nuts93. It will readily be comprehended that when the carrier '48 is movedfrom the position shown in Fig. 4 to that shown in Fig. 3 that theblades 69 and 92 are brought into engagement with the jaws 9] and thefuse I9 connected in the circuit, and that when the carrier is moved tothe position shown in Fig. 4 the blades are disconnected from the switchjaws and the fuse is isolated from the circult.

.F'or moving the carrier 48 two links 94 and 95 are employed. Theselinks are pivoted to lugs 96 which are secured to the welding or in anyother link 94 has a slot 9! suitable manner. The in it which receives apin 98 attached to an angle bracket 99 which is secured to the'carrier'48 by means of bolts I III. The pin 98 can slide in the slot 9! so thatthe door 29 can be closed whether the carrier 48 is in similarlyconstructed and is best shown in Fig. 4. This link has a longitudinallyextending slot I92 which is bayonet in form and is provided with a andan offset portion A pin I84 extending through an arm I05-is and may ridealong the an adjusting screw II2. This screw may engage a lug I I3formed on the bracket I91 whereby the swinging of the arm I05 in anupward direction is restrained. The link 95 and the link 94 operate inunison to disengage the switch from the jaws 9I switches when the tlonshown in Fig.

and to permit of opening the door 29 is moved to the posi- 4. It will benoted that both panel 3| of door 29 by 1 switch; opening orswitch-closing position. The link 95 is- H9 or enter the offset por Thisarm is pivoted by means of a the arm I95 therebeblades 59 and 82.

iii)

of the links 94 and 95 are constructed with "off sets II4 which causethe said links to engage the flanges 33 of the door 29 and to limitswinging movement of the door relative to said links.

Extending across the uprights 39 of the frame--v work 38 adjacent thelink 94 is an angle cross frame member 5. This frame member is welded tosaid uprights and has attached to itby means of bolts H8 an arcuateguide III. This guide is constructed with a notch I I8 best shown inFig. 3 and which forms a shoulder II9 facing outwardly of the guide. Theguide II! has an arcuate surface I2I which is concentric with the axisof the hinge 5| for the carrier 48. The arm I 85 has attached to theunderside thereof a latch lug I22 which is adapted to ride on thesurface I2I as the carrier 48 swings from one position to the other.When the latch lug I22 reaches the notch H8, it drops into said notchand the shoulder H9 restrains movement of the carrier intoswitch-closing position.

Extending through the plate I88 is a bolt I23 which is provided with anut I24 and a lock nut I25. A compression coil spring I28 encircles thisbolt and is seated at one end against the plate I88 and at its other endagainst the head I21 of said bolt. This head is adapted to engage a lugI 28 cast on the guide Ill and serves as a bumper for absorbing theshock when the blades 69 and 82 are disengaged from the jaws 9| and thecarrier is brought into switch opening position.

For checking the movement of the door 29, a door check I29 is employedwhich is pivoted to a block I3I secured to one of the angle framemembers 85. This door check has a piston rod I32 which is pivoted to abracket I33 fastened on the door 29. In this manner, slamming the doorduring either opening or closing operations does not injure the door orthe structures controlled thereby.

To further safeguard the operator in the removal of fuses from the fuseholders, a grounding device I3! is used for each fuse holder. Thisgrounding device consists of a contact blade I38 having a curved leadingedge I39. The said blade is supported on a flexible hanger I4I which issecured to a clip I42. Clip I42 is mounted on an angle cross framemember I43 which is attached to the upper frame 38 of the framework 36.When the carrier 48 is moved into switch-open-, ing position, the clip84 engages the contact blade I38 and the same are grounded through theframework 38 and the main framework II.

The method of operation of the invention is as follows:

Assume that the door 29 is closed as shown in Figs. 1 and 3 and-that theswitches ?2, I3 and 74 are in closed position. Pins 68 and IE4 are atthe ends of the slots 91 and W2 of links 94 and 95. Outward movement ofthe door 29, hence, causes both of these links to disengage the blades89 and 82 from theswitch jaws SI and to swing the door to the positionshown in Fig. 4. As the carrier 48 is moved forwardly, the lug I22 ridescnthe surface iZI of guide .I I1 until it drops into the notch H8. Asthe said carrier reaches this position, the head i2? of bolt I23 engageslug I 28 and the movement of the said carrier is retarded. When the lugI22 is received in slot H8, as shown in Fig. 4, the carrier 48isrestrained from movement. In such position the fuse holders l5, l8 andTi are completely disconnected from the line and safety to the operatorfrom high voltage is assured. Additionally,.the upperclips, namely,theiuse clips 64-;e1i'g'age' the contact blade I38 of the groundingdevice l3! and the safety of the operator is further assured; As thedoor opens, the check l29 prevents slamming of the door into openposition. The links 94 engaging the flange 33 of. door 29 at the bottomof the samehold the door in the position shown in Fig; l. The fuses arenow at the front ofthe opening 2| where the same may be inspected orexchanged as the occasion requires. If, during opening of the door, aflash-over occurs, the same is prevented from injuring the operator dueto the barriers l34.- The dimensions of the carrier 48 are such thatwhen the said carrier is in switch-opening position, as shown in Fig. 4,the said carrier substantially closes the openin 21 and prevents theoperator from accidentally coming in contact withany of the live partswithin the interior of the enclosure. At thesame time the groundingdevices insure that the fuse holders are at ground potential. The weightof the link 94 causes the pin I04 to be received in the offset portion33 of slot I02. Upon closing of the door the arm I05 is first movedupwardly due to the direction of thrust of the link 94 and lug I22 isdisengaged from notch Hi3. When bolt H2 strikes lugs H3 movement of thearm :55 is terminated and further movement of the door causes-carrier 48to swing about the axis of the hinge iii;

The carrier is then moved into position so that the blades 59 of thevarious fuse holders engage the switch jaws 9i and connect the fusesback into the circuits which they serve. If at any time, itbecomesdesirable to leave the carrier 48 in switch-opening position, link 94may be manually raised to disengage the pin IE4 from the offset portionifi3 of slot I92. As the door is closed, the pin I84 then travels alongthe longitudinal portion H0 of said slot and the door 29 may be s dwithout interfering with th J in its switch-opening position.

The advantages of the invention are manifest. The structure is foolproofin operation and completely prevents high voltage accidents or hazardsto the operator when changing or inspecting the fuses. It becomesimpossible for the operator to inject his hand into the interior of theenclosure until after the switches have been opened and fusesdisconnected. After the switches are opened, the carrier closes theaccess opening and the disconnected parts are then accessible'forinspection and exchange of-fuses. The structure shown is particularlyapplicable to high-voltage circuits. The switch and fuse constructionembodying the invention can be constructed at a nominal expense and willoperate indefinitely without requiring attention. Changes in thespecific form of the invention, as herein described, may be made withinthe scope of .what is claimed without departing from the spirit of theinvention. 7

Having described the invention, what is claimed as new and desired to beprotected by Letters Patent is: 1. In combinatioman enclosure having anaccess opening therein, a door for said opening pivoted ,to saidenclosure near an edge thereof and adapted to swing outwardly from saidopening, a fuse carrier separate from said door disposed inwardly ofsaid opening and pivoted to a part fixed relative to said enclosure andmovable toward and from said opening, a fuse carried by said fusecarrier and having a fuse contact. an electrical terminal disposedinwardly of said access opening and fuse, a terminal con- 8.tac't'hohnected tosaid 'terininaland adapted to make contact with thefuse contact when the fuse carrier is in its innermost position and tobecome disconnected therefrom when the fuse carrier is'moved toward saidopening, said carrier being of substantially the same area as the areaof said access openin and serving to close said opening when the fusecontact is disconnected from the terminalcontact, and linkage betweensaid fuse carrier and door, said linkage bringing saidcarrier intoclosing position when the door is in open position. 2. Incombination,'an enclosure having an access opening therein, a door forsaid opening pivoted to said enclosure near an edge thereof and adaptedto swing outwardly from said'op'ening, a fuse carrier separatefrom saiddoor including a plate disposed inwardly of said open-,-. ing andpivoted to a part fixed relative to said enclosure and movable towardand from said opening, a fuse carried by said fuse carrier and" having afuse contact, an electrical terminal dis-z posed inwardly of said accessopening and fuse, a terminal contact connected to said terminal andadapted to make contact with the fuse c0ntact When the fuse carrier isin its innermost position' and to become disconnected therefrom when thefuse carrier is moved toward said opening, said plate being ofsubstantially the same area as the area of said access opening andserving to close said opening when the fuse contact is disconnected fromthe terminal contact, and linkage between said fuse carrier and door,said link age bringing said carrier into closing position when thedooris in open position.

3. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and fuse, a terminal contactconnected to said terminal and adapted to make contact with the fusecontact when the fuse carrier is in its inner-- most position and tobecome disconnected therefrom when the fuse carrier is moved toward saidopening, said carrier being of substantially the'same: area as the areaof said access openingv and serving to close said opening when the fusecontact is disconnected from the terminal contact, a link pivoted toa'part carried by'said door and extending inwardly thereof, connectingmeans between said link and fuse carrier, said link being adapted tooccupy two positions relative to said connecting means, said link in'one position being restrained from movement in the direction of itslength relative to said fuse carrier to cause movement of the fusecarrier upon movement of said door, and in its other position beingadapted to move in the direction of its length relative to the carrierto accommodate closing of the door when the fuse carrier isi'n itsoutermost position and the contacts are disconnected.

4. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to apart fixed relativetosaid'enclosure and movable toward andfrom' accuses said opening, afuse carried by said fuse carrier and having a fuse contact, anelectrical terminal disposed inwardly of said access opening and fuse, aterminal contact connected to said terminal and adapted to make contactwith the fuse contact when the fuse carrier is in its innermostposit-ion and to become disconnected therefrom when the fuse carrier ismoved toward said opening, said carrier being of substantially the samearea as the area of said access opening and serving to close saidopening when the fuse contact is disconnected from the terminal contact,a link pivoted to a part carried by said door and extending inwardly ofthe door, connecting means between said link and fuse carrier, said linkbeing adapted to occupy two positions relative tosaid connecting means,said link in one position being restrained from movement in thedirection of its length relative to said fuse carrier to cause movementof the fuse carrier upon movement of said door, and in its otherposition being adapted to move in the direction of its length relativeto the fuse carrier to accommodate closing of the door when the fusecarrier is in its outermost position and the contacts are disconnected,and locking means acting between said enclosure and carrier and holdingsaid carrier from movement when in its outermost position. v

5. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said openi g, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and fuse,

a terminal contact connected to said terminal and adapted to makecontact with the fuse contact when the fuse carrieris in its innermostposition and to become disconnected therefrom when the fuse carrier ismoved toward said opening, a link pivoted to a part carried by said doorand extending inwardly of said door, connecting means between said linkand fuse carrier, said link'being adapted to occupy two positionsrelative to said connecting means, said link in one position beingrestrained from movement in the direction of its length relative to saidfuse carrier to cause movement of the fuse carrier upon movement of saiddoor, and in its other position being adapted to move in the directionof its length relative to the fuse carrier to accommodate closing of thedoor when the fuse carrier is in its outermost position and the contactsare disconnected, guide means carried by said en closure and engaging apart carried by said link, and lock means carried by said guide meansand engageable with a part carried by said fuse carrier and holding thefuse carrier in its outermost position.

6. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadaptedto swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and fuse, a terminal contactconnected to said terminal and adapted to make contact with the fusecontact when the fuse carrier is in its innermost position and to becomedisconnected therefrom when the fuse carrier is moved toward saidopening, a link pivoted to a part carried by said door and extendinginwardly thereof, said link being formed with a bayonet slot having alongitudinal portion and an offset portion, a pin carried by the fusecarrier and movable along said slot, said pin when in said offsetportion thereof causing movement of the fuse carrier upon movement ofthe door and when in said longitudinal portion accommodating slidingmovement of the link relative to the pin when the fuse carrier is in itsoutermost position to close the door without causing movement of thecarrier.

7. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof and.adapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and. fuse, a terminal contactconnected to said terminal and adapted to make contact with the fusecontact when the fuse carrier is in its innermost position and to becomedisconnected therefrom when the fuse carrier is moved toward saidopening, a link pivoted to a part carried by said door and extendinginwardly of said door, said link being formed with a bayonet slot havinga longitudinal portion and an oifset portion, an arm pivoted to a partcarried by said fuse carrier, a pin carried by said arm and extendingthrough said slot, and adapted to be received either the longitudinalportion of the bayonet slot or the ofiset portion thereof, a guide, alug on said arm engaging said guide and movable along the same, saidguide having a, notch therein near one end into which said lug may enterupon movement of the lug, said notch forming a shoulder restrainingmovement of said lug and preventing inward movement of said fuse carnor.

8, In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a, part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and fuse, a terminal contactconnected to said terminal and adapted to make contact with the fusecontact when the fuse carrier is in its innermost position and to becomedisconnected therefrom when the fuse carrier is moved toward saidopening, a link pivoted to a part carried by said door and extendinginwardly of said door, said link being formed with a bayonet slot havinga longitudinal portion and an offset portion, an arm pivoted to a partcarried by said fuse carrier, a pin carried by said arm and extendingthrough said slot, and adapted to be received in either the longitudinalportion of the bayonet slot or the offset portion thereof, a guide, 3,lug on said arm engaging said guide and movable along the same, saidguide having a notch therein near n end n o which a d lug m ente ponmovement of the lug, said notch forming a shoulder restraining movementof said lug and preventing inward movement of said fuse carrier, saidlink being independently movable relative to said pin when the pin is insaid notchto bring thepin into the longitudinal portion of the slot inthe link for accommodating movement of the link independently of thefuse carrier to close the door.

9. In combination, an enclosure having an access opening therein, a doorfor said opening pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier and having a fuse contact, an electrical terminaldisposed inwardly of said access opening and fuse, a terminal contactconnected to said termina1 and adapted to make contact with the fusecontact when the fuse carrier is in its innermost position and to becomedisconnected therefrom when the fuse carrier is moved toward saidopening, a link pivoted to a part carried by said door and extendinginwardly of said door, said link being formed with a bayonet slot havinga longitudinal portion and an offset portion, an arm pivoted to a partcarried by said fuse carrier, a pin carried by said arm and extendingthrough said slot, and adapted to be received in either the longitudinalportion of the bayonet slot or the offset portion thereof, a guide, alug on said arm engaging said guide and movable along the same, saidguide having notch therein near one end into which said lug may enterupon movement of the lug, said notch forming a shoulder restrainingmovement of said lug and preventing inward movement of said fuse carrierand stop means for restraining movement of said arm in one directionrelative to said carrier to force said latch lug out of said notch uponinitial movement of the door toward closing position.

10. In combination, a grounded enclosure having an access openingtherein, a door for said opening pivoted to said enclosure near an edgethereof and adapted to swing outwardly from said opening, a fuse carrierdisposed inwardly of said opening and pivoted to a part fixed relativeto said enclosure and movable toward and from said opening, saidfuse-carrier including a fuse clip, a fuse mounted in said clip, saidclip having a fuse contact, an electrical terminal disposed inwardly ofsaid access opening and fuse, a terminal contact connected to saidterminal and adapted to make contact with the fuse contact when the fusecarrier is in its innermost position and to become disconnectedtherefrom when the fuse carrier is moved toward said opening, agrounding contact electrically connected to and carried by saidenclosure and adapted to make contact with said clip upon disconnectionof the fuse contact from the terminal contact, and linkage between saidfuse carrier and door, said linkage bringing said carrier into closingposition; when the door is in open position.

11. In combination, an enclosure having an access opening therein, adoor for said openin pivoted to said enclosure near an edge thereof andadapted to swing outwardly from said opening, a fuse carrier disposedinwardly of said opening and pivoted to a part fixed relative to saidenclosure and movable toward and from said opening, a fuse carried bysaid fuse carrier, a fuse contact in contact with said fuse, anelectrical terminal disposed inwardly of said access opening and fuse, aterminal contact connected to said terminal and adapted to make contactwith the fuse contact when the fuse carrier is in its innermost positionand to become disconnected therefrom when the fuse carrier is movedtoward said opening, said carrier being of substantially the same areaas the area of said access opening and serving to close said openingwhen the fuse contact is disconnected from the terminal contact,barriers at the sides of said carrier and extending outwardly therefromtoward said opening, and a linkage between said fuse carrier and door,said linkage bringing said carrier into closing position when theclosure is in open position.

12. In combination, an enclosure having a vertically disposed accessopening, a door extending across said opening, pivot means for said doordisposed substantially at the lowermost portion thereof, said door beingadapted to swing through an angle greater than a fuse carrier disposedinwardly of said opening and normally extending in a rearwardly inclineddirection with its lower edge disposed rearwardly of said door, pivotmeans for said carrier disposed substantially at the lowermost edgethereof and having its axis parallel to the axis of the pivot means forthe door, and a link connected to said carrier and to said door and tothe carrier at a greater distance from the pivot of the same than thedistance from the pivot means for the door to the connection between thedoor and link, whereby the carrier is moved to a substantially verticalposition upon the swinging of the door through out its extent.

13. In combination, an enclosure having an access opening therein, adoor for said opening, a pivot for pivoting said door to said enclosurenear an edge thereof, said door being adapted to swing outwardly fromsaid opening, a fuse carrier planiform in shape pivoted to saidenclosure near said pivot to swing outwardly in the same direction assaid door, said carrier being disposed inwardly from said door, a fusecarried by said fuse carrier and mounted on the surface of said carrierfacing said door, an electrical terminal disposed within said enclosure,a terminal contact disposed inwardly of said fuse carrier and connectedto said terminal, a fuse contact'on the other surface of said carrierand normally engaging said terminal contact and linkage between saidfuse carrier and door, said linkage serving to swing said carrier towardsaid access opening to disengage said contacts and move said fuse intoaccessible position when the door is opened. a

l4. In combination, an enclosure having'an access opening therein andbeing provided with a supporting structure extending inwardly from anedge of the opening, a door normally closing said opening, a firstpivotfor said door disposed at said edge of the opening and attached tosaid door and supporting structure, said pivot guiding said doorforoutward swinging movement to uncover said opening, a fuse carrierdisposed within said enclosure inwardly of said door, a second pivot forsaid carrier having its-axis par.- allel to the axis of said door anddisposed inwardly of said opening, said second pivot being connected tosaid carrier and supporting structure, a fuse carried by said carrier, afixed teiminal, contact means between said terminal and fuse and adaptedto be disconnected upon move merit of said carrierin an outwarddirection, and

linkage between said fuse carrier and door, said linkage serving toswing said carrier toward said access opening to disengage said contactsand move said fuse into accessible position when the door is opened.

l5. In combination, an enclosure having an access opening therein, adoor for said opening, a first pivot for pivoting said door to saidenclosure near an edge thereof, said door being adapted to swingoutwardly from said opening, a fuse carrier, a second pivot between saidcarrier and supporting structure and supporting said carrier to swingoutwardly in the same direction as said door, said carrier beingdisposed inwardly from said door, a fuse carried by said fuse carrier,an electrical terminal disposed within said enclosure, contact meansbetween said terminal and fuse and adapted to be disconnected uponmovement of said carrier in an outward direction, a link between saiddoor and carrier, a third pivot between said carrier and link, a fourthpivot between said door and link, said third pivot being further fromthe second pivot than the distance between the fourth pivot and thefirst pivot whereby the door may be moved to a fully-open position whilethe carrier is being moved a distance suflicient to disengage saidcontacts.

JOHN S. FERGUSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,073,281 Palmer Sept. 16, 1913 1,402,123 Wadsworth Jan. 3,1922 2,404,230 Harlow et a]. July 16, 1946

